ADR-013 Phase 4: all 13 plugin frontends relocated + staging machinery

frontend/vitest.config.js

@@ -14,6 +14,8 @@ export default defineConfig({
   test: {
     environment: 'jsdom',
     globals: true,
+    // Core specs plus plugin-frontend specs, which the pretest stage copies
+    // into src/.plugins-staged/ (under root, so this glob finds them).
     include: ['src/**/*.spec.js'],
   },
 })